From RestOfWorld, The hidden labor that makes AI work:

This industry has been called by many names: “crowdwork,” “data labor,” or “ghost work” (as the labor often goes unattended and unseen by consumers in the West). But this work is very visible for those who perform it. Jobs in which low-paid workers filter out, correct, or label text, images, videos, and sounds have been around for nearly as long as AI and the current era of deep learning methods has been. It’s not an exaggeration to say that we wouldn’t have the current wave of “AI” if it weren’t for the availability of on-demand laborers.

… Modern slavery.